#include <stdio.h>


int main()
{
    FILE* pf = fopen("log.txt","w");
    if(pf ==NULL)
    {
        perror("fopen");
        return 1;
    }
    fprintf(pf,"helloworld,%d,%s,%lf\n",10,"ghs",3.14);
    
    fclose(pf);
    return 0;
}
